Significance
Progression from a preleukemic state to transformation, in the presence of TET2 mutations, is coupled with the emergence of inflammation and a novel population of inflammatory monocytes. Genes characteristic of this inflammatory population are associated with the worst prognosis in patients with AML. These studies connect inflammation to progression to leukemia. See related commentary by Pietras and DeGregori, p. 2234 . This article is highlighted in the In This Issue feature, p. 2221.